Cant view it because imgur, but if it’s like you describe perhaps either:

• The marches are more pro-Zionist than against antisemitism.
• The organizers to do some housecleaning and clear the Zionists out of their marches.

EDIT:

I saw the alternative link, and the amount of booing and Israel flags tell me that the Zionists are far from a small minority here.

As someone who is against antisemitism, genocide and Islamophobia, I would feel deeply uncomfortable being at that rally.